How does a sub deal with excessive arousal?

I'm struggling with mindset when getting horny.

Basically I want to make our sex centered around my wife's pleasure. The problem is that I get so damn aroused when she takes control that I completely lose it.

I become perverted, bratty and focused on my own pleasure instead of hers. In my mind following her commands quickly becomes an almost masturbatory act. My fantasies about certain kinks take center stage and in more than one occasion I've blurted out something about them. While I don't have a problem sharing my kinks, there is a time and a place for that and that is certainly not during play.

I don't want her to feel like she's my kink dispenser nor do I want to make her feel uncomfortable. I want her to feel like I'll serve her every whim. I want her to feel like she's the center of my universe.

How do I learn to better control my hornyness and be a better servant to my goddess?